The study determined efficacy of different phytases in diets without inorganic phosphorus (P) in piglets. Piglets (initial body weight 9.7 ± 1.2 kg) were randomly assigned (2 piglets/pen), based on sex and body weight over 6 diets. Positive control (PC) corn-wheat based diet was formulated to meet NRC specification. Negative control (NC) diet was formulated without inorganic P (-0.16% STTD P), with reduced calcium (Ca; -0.15%), net energy (-33 kcal/kg), and standardized ileal digestible amino acids (average -0.02% unit). The NC diets were supplemented with 4 different phytases at 1,500 FTU/kg feed including a novel consensus bacterial 6-phytase variant expressed in Trichoderma reesei (PhyG), a Citrobacter braakii phytase expressed in Aspergillus oryzae (PhyC), a hybrid phytase (Hafnia sp., Yersinia sp. and Buttiauxella sp.) expressed in Aspergillus niger (PhyH) and an Escherichia coli phytase expressed in Pichia pastoris (PhyE). Piglets were fed ad libitum for 42 d. Fecal samples were collected during last 3 d. On d 42, 1 piglet per pen was euthanized and metacarpi collected for bone strength and ash analysis. Data were analysed by one-way ANOVA and treatment mean comparison by Tukey test using JMP 14. Pigs fed NC diets showed reduced (P < 0.05) growth, P digestibility, bone ash and bone strength vs PC and all phytases treatments. Overall feed conversion ratio (FCR) was less (P < 0.05) with PhyG (-22 points) and PhyE (-8 points) vs NC, while PhyC and PhyH showed intermediate FCR between PhyG and PhyE. PhyG improved (P < 0.05) bone strength and P digestibility vs PhyC, PhyE and PC. Based on FCR and bone strength, ranking of the phytases are: PhyG >PhyC >PhyH >PhyE. In conclusion, all phytases improved growth, nutrient digestibility and bone strength vs NC; however, only PhyG fully compensated nutrients and energy reduction, fully recovered performance to the level of PC and resulted in improved bone strength compared with PC.
The objective was to test the hypothesis that dietary P concentration and level of phytase influences basal endogenous loss of Ca in pigs. Seventy barrows (body weight: 17.66 kg) were housed in metabolism crates and allotted to 7 Ca-free diets containing corn, potato protein concentrate, and full-fat rice bran (0.27% phytate P). A positive control (PC) diet contained P at the requirement for digestible P for 11 to 25 kg pigs. Negative control (NC) diets were formulated by reducing concentration of digestible P by 0.15% and adding a novel consensus bacterial 6-phytase variant at 0, 250, 500, 1,000, 2,000, or 4,000 phytase units/kg diet. Feces and urine samples were collected separately for 4 d after 5 d of adaptation. Dried and ground fecal samples were analyzed for dry matter, Ca, and P and urine was analyzed for P. Data were analyzed using a model that included diet as fixed effect. Positive control and NC were compared using a contrast statement and linear and exponential effects of dietary phytase were tested. Results indicated that apparent total tract digestibility of dry matter was not affected by dietary P or phytase (Table 1). The basal endogenous loss of Ca was not affected by dietary P, but exponentially (P = 0.030) decreased as dietary phytase increased. Phosphorus retention (g/d) was greater (P < 0.001) in pigs fed PC compared with NC without phytase. The standardized total tract digestibility (STTD) of P exponentially (P < 0.001) increased as phytase increased; however, retention of P as % of absorbed P decreased (linear, P = 0.006) as phytase increased because the extra P absorbed as a result of phytase could not be retained due to the lack of Ca. In conclusion, increasing the phytase dose decreased basal endogenous loss of Ca and increased STTD of P.
An experiment was conducted to test the hypothesis that increasing levels of phytase increases apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients in diets fed to young pigs. A negative control (NC) diet that was deficient (compared with NRC recommendation) in total Ca (-0.15%), standardized total tract digestible P (-0.16%), net energy (-33 kcal/kg), and standardized ileal digestible amino acids (average -0.02% unit) was formulated. Five additional diets were formulated by adding 250, 500, 1,000, 2,000 or 4,000 phytase units per kg of a novel consensus bacterial 6-phytase variant (PhyG) to the NC diet. All diets were based on corn, soybean meal, and canola meal. Eighteen ileal-cannulated pigs (17.81 ± 1.71 kg) were allotted to a 6 × 3 incomplete Latin square design with 6 diets and 3 periods. There were 3 pigs per diet in each period; therefore, there were nine replicate pigs per diet. Data were analyzed using the Mixed Procedure of SAS with diet as the fixed effect whereas pig and period were considered random effects. Linear and quadratic effects of PhyG on nutrient digestibility were determined using polynomial contrast statements. Linear (P < 0.01) and quadratic (P < 0.05) increases in AID of all individual amino acids (except Arg) were observed as dietary concentrations of PhyG increased (Table 1). Likewise, an increase (linear, P < 0.01; quadratic, P < 0.05) in ATTD of minerals in diets was observed as the concentration of PhyG increased in diets. Increasing levels of PhyG in diets also increased (linear, P < 0.05) ATTD of gross energy. In conclusion, increasing levels of the novel phytase (PhyG) effectively increased ileal and total tract digestibility of nutrients by pigs.
A meta-analysis was conducted to evaluate the effect of a multi-enzyme complex (MEC) on growth performance in weaned piglets [initial body weight (BW) of 7.6±1.2 kg]. Database was constructed using 4 unpublished studies, contributing 306 data points. The dietary treatments consisted of a conventional diet (CC) with highly digestible nutrients, a high-fiber, low-digestible protein diet (NC), and the NC supplemented with MEC. All diets were corn/wheat/soybean meal based, formulated to meet or exceed NRC specification for weaned piglets. The NC contained ingredients such as barley, distiller's dried grains with solubles, wheat middling, rye and rapeseed meal depending on the geographic location of the study. In all studies, MEC provided 4,000 U/kg Xylanase, 200 U/kg β-glucanase, 100 U/kg Amylase, and 2,000 U/kg Protease. All diets contained 750 FTU/kg of a commercial Buttiauxella phytase. Piglets were fed experimental diets over 2 phases for 42 d, from d 1 of weaning. Growth performance was recorded bi-weekly. Data were analyzed using Mixed Model by JMP 14.0. The average daily gain of piglets fed MEC supplemented diets was increased by 7.4% vs NC (P = 012) during phase 1. The final BW (d 42) was improved by 1.1 kg (4.1%; P = 0. 037) in piglets fed MEC supplemented diets compared with NC. Respective improvements (P < 0.05) in feed conversion ratio during phase 1 and overall were 11% (16 points) and 4.4% (7 points) in MEC supplemented diets when compared with NC, which indicates better nutrient digestibility. In conclusion, supplementing a high fiber weaner diets with a multi-enzyme complex improved final BW and feed efficiency in piglets.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.